Answer
To make 12 brownies, you need:
$\frac{1}{2}$ cup of butter, 3$\frac{3}{4}$ ounces of unsweetened chocolate, 1$\frac{1}{8}$ cups of sugar, 1$\frac{1}{2}$ teaspoons of vanilla, 1$\frac{1}{2}$ eggs, and $\frac{3}{4}$ cup of flour
Work Step by Step
To make 12 brownies using a recipe designed to make 16 brownies, first divide 12 by 16. We get $\frac{3}{4}$. We need to multiply each ingredient measure for 16 brownies by $\frac{3}{4}$.
To make 16 brownies, we need $\frac{2}{3}$ cup of butter. Adjusting for 12 brownies, we multiply $\frac{2}{3}$ by $\frac{3}{4}$. This means we need $\frac{6}{12}$ which reduces to $\frac{1}{2}$ cup butter.
We need 5 ounces of unsweetened chocolate for 16 brownies. To adjust to 12 brownies, we multiply $\frac{5}{1}$ x $\frac{3}{4}$. This means we need 3$\frac{3}{4}$ (3.75 in decimal form) ounces of unsweetened chocolate.
For 16 brownies, we need 1$\frac{1}{2}$ cups of sugar. We convert mixed numerals to improper fractions before we multiply. $\frac{3}{2}$ x $\frac{3}{4}$ = $\frac{9}{8}$ cup of sugar. This equals 1$\frac{1}{8}$ cups of sugar.
We need 2 teaspoons of vanilla for 16 brownies. To make 12 brownies, we need $\frac{2}{1}$ x $\frac{3}{4}$ = $\frac{6}{4}$ = $\frac{3}{2}$, or 1.5 teaspoons of vanilla.
For 16 brownies, 2 eggs are needed. To make 12 brownies, $\frac{2}{1}$ x $\frac{3}{4}$ which is $\frac{3}{2}$ or 1.5 eggs.
Last, we need 1 cup of flour for 16 brownies. To adjust to 12 brownies, we multiply 1 by $\frac{3}{4}$ which means we need $\frac{3}{4}$ cup of flour.
